A 3D-IC (integrated circuit) memory technique may be used to increase a memory capacity. The 3D-IC memory technique generally refers to technology related to arranging memory cells three-dimensionally.
One 3D-IC technique is a “punch-and-plug” technique. The punch-and-plug technique includes sequentially forming multi-layered thin layers on a substrate and then forming plugs to penetrate the thin layers. Through this technique, without a drastic increase in manufacturing costs, a three-dimensional memory device may be made having an increased memory capacity.